A powerful investors’ advisory group has called for shareholders to vote against the $99m (£73m) pay package awarded to Apple boss Tim Cook last year.

In a letter to shareholders, the advisory firm Institutional Shareholder Services (ISS) wrote there were “significant concerns regarding the design and magnitude of the equity award” made to Cook in 2021, adding that half of the award “lacks performance criteria”.

ISS had made the recommendation for when the company’s shareholders meet next month.

Cook, 61, has a personal fortune of $2.3bn, according to Forbes, and has been a vocal critic of social and economic inequality. He has pledged to give away his fortune before his death.

Last year, Cook took h